Calorimetry measurements are commonly utilized in biophysical and biochemical studies to determine energy changes as indications of biochemical reactions in a media. Prior techniques for measurements include using electrodes, thermopiles, optical techniques, and microcalorimeters for measurements within a sampled media. There is a great interest in developing ultra-miniature microcalorimeter devices that require very small volumes of sampled media for accurate detection and measuring of biochemical reactions on, or in close proximity to, the microcalorimeter.
In Thundat et al., U.S. Pat. No. 5,719,324, a piezoelectric transducer is disclosed that is fabricated with a cantilever having a spring element treated with a chemical having an affinity for a specific vapor phase chemical. An oscillator means maintains a resonant vibrational frequency during detection of a chemical, with changes in resonant frequency indicating amounts of targeted chemical detected in the monitored atmosphere.
In Wachter et al., U.S. Pat. No. 5,445,008, a mass microsensor is disclosed that is fabricated with a microcantilever, that oscillates due to a piezoelectric transducer, with a chemical coating on the microcantilever that absorbs a targeted chemical from the monitored atmosphere. The resonant frequency of the microcantilever is analyzed to determine changes that indicate amounts of targeted chemical detected in the monitored atmosphere.
In Marcus et al., U.S. Pat. No. 5,475,318, a microprobe is disclosed that includes a microcantilever, a base, a probe tip projecting from the base, and a heating element that heats the probe tip, which comes into contact with a material to be investigated.
In Hafeman, U.S. Pat. No. 4,963,815, a device and method is provided for determining an analyte by measuring a redox potential-modulated photoinducing electrical signal from an electronically conducting layer on a semiconductor device.
In Kolesar, U.S. Pat. No. 4,549,427, a chemical nerve agent detector is disclosed that includes a transducer having two microcantilever oscillators. The active microcantilever of the two microcantilevers has a chemically selective substance that absorbs chemical nerve agents from the atmosphere, with modifications in the oscillation of the active microcantilever, and comparisons are made between the frequency of the active cantilever and the reference cantilever.
The above described methods and devices of measuring chemical and micromechanical parameters in sampled media have numerous shortcomings. The prior art does not provide for detecting and monitoring by an apparatus of low thermal mass of heat exchanges of chemical reactions related to biomolecules as the reactions occur in a sample of monitored media. Thus there exists room for improvement within the art. The subject invention provides a novel approach to sampling of thermal changes in a media utilizing extremely small sample volumes of media.